L-pipecolic acid (L-PIP) (CAS Reg. #535-75-1) is a nonprotein amino acid that is widely distributed in higher and lower plants. L-PIP is also derived via lysine catabolism in many organisms.
L-PIP has anorectic (appetite reducing) effects in animals. As an example, it was shown that ICV injection of L-PIP inhibited food intake and induced sleep-like behavior in chicks (Takagi et al., Neurosci. Lett., 2001, 310:97-100). It is believed that L-PIP's anorectic effects are mediated by L-PIP's interaction with various molecular components in the brain such as neuropeptide Y (NPY). NPY is a 36-residue peptide neurotransmitter that is a potent stimulator of feeding. There is a natural afferent signal to the lateral hypothalamic area associated with NPY that results in appetite stimulation. It is believed that L-PIP interferes with this signal resulting in anorectic effects.
The anorectic effects of L-PIP are undesirable, particularly in cattle production due to lower feed intake resulting in lower weight gain and an increase in overall beef production costs. In dairy cattle the anorectic effects can lead to an increase in milk production costs. L-PIP may also cause other undesirable effects in the brain. For example, L-PIP is known to induce apoptosis in neuronal cells (Matsumoto, Brain Res., 2003, 980:179). High levels of L-PIP have also been associated with Zellweger syndrome, Refsum disease, and various peroxisomal disorders.
Therefore, a need exists for methods and compositions for reducing the effects of L-pipecolic acid.